The dependence of \(T_c\)  on pressure for the present ternary La\(_{0.5}\) Ce\(_{0.5}\) H\(_{10}\)  and the binary LaH\(_{10}\)  and CeH\(_{10}\)  from earlier works [1]}, [2]}, [3]}, [4]} is summarized in Fig. 5. \(T_c\)  of La\(_{0.5}\) Ce\(_{0.5}\) H\(_{10}\)  just lies at the middle points of the \(T_c^{\prime }\) s of the respective binary hydrides. Meanwhile, the Fmm La\(_{0.5}\) Ce\(_{0.5}\) H\(_{10}\)  can be dynamically stabilized in the studied pressure range of 140-160 GPa. However, a monoclinic structural distortion leads to the C2/m phase in the binary LaH\(_{10}\)  hydrides below the pressure of 160 GPa [4]}. Therefore, it can be appraised that the 4f electrons in Ce metal are effective to reduce the stabilization pressure of the phases with high hydrogen content of 10.
